package util;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
public class Verify {
	private int w=70;
	private int h=35;
	private Random r=new Random();
	//{"宋体","华文楷体","黑体","华文新魏","华文隶书","微软雅黑","楷体_GB2312"}
	private String[] fontNames={"宋体","华文楷体","黑体","华文新魏","华文隶书","微软雅黑","楷体_GB2312"};
	//可选的字符
	private String codes="23456789qwertyuiopasdfghjkzxcvbnmQWERTYUIOPASDFGHJKZXCVBNM";
	//背景色
	private Color bgColor=new Color(255,255,255);
	//验证码上的文本
	private String text;
	
	//生成随机的颜色
	private Color randomColor() {
		int red=r.nextInt(150);
		int green=r.nextInt(150);
		int blue=r.nextInt(150);
		return new Color(red,green,blue);
	}
	
	
	//生成随机的字体
	private Font randomFont() {
		int index=r.nextInt(fontNames.length);
		String fontName=fontNames[index];//生成随机的字体名称
		int style=r.nextInt(4);//生成随机的样式,0(无样式)，1(粗体)，2(斜体)，3(粗体+斜体)
		int size=r.nextInt(5)+24;//生成随机字号，24 - 28
		return new Font(fontName,style,size);
	}
	
	//画干扰线
	private void drawLine(BufferedImage image) {
		int num=3;//一共画3条
		Graphics2D g2=(Graphics2D)image.getGraphics();
		for(int i=0;i<num;i++) {//生成两个点的坐标，即4个值
			int x1=r.nextInt(w);
			int y1=r.nextInt(h);
			int x2=r.nextInt(w);
			int y2=r.nextInt(h);
			g2.setStroke(new BasicStroke(1.5F));
			g2.setColor(Color.BLUE);//干扰线是蓝色的
			g2.drawLine(x1, y1, x2, y2);//画线
		}
	}
	
	
	//随机生成一个字符
	private char randomChar() {
		int index=r.nextInt(codes.length());
		return codes.charAt(index);
	}
	
	//创建BufferedImage
	private BufferedImage createImage() {
		BufferedImage image=new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
		Graphics2D g2=(Graphics2D)image.getGraphics();
		g2.setColor(this.bgColor);
		g2.fillRect(0, 0, w, h);
		return image;
	}
	
	//调用这个方法得到验证码
	public BufferedImage getImage() {
		BufferedImage image=createImage();//创建图片缓冲区
		Graphics2D g2=(Graphics2D)image.getGraphics();//得到绘制环境
		StringBuilder sb=new StringBuilder();//用来装载生成的验证码文本
		//向图片中画4个字符
		for(int i=0;i<4;i++) {//循环4次，每次生成一个字符
			String s=randomChar()+"";//随机生成一个字符
			sb.append(s);//把字母添加到sb中
			float x=i * 1.0F * w / 4;//设置当前字符的x轴坐标
			g2.setFont(randomFont());//设置随机字体
			g2.setColor(randomColor());//设置随机颜色
			g2.drawString(s, x, h-5);//画图
		}
		this.text=sb.toString();//把生成的字符串赋给了this.text
		drawLine(image);//添加干扰线
		return image;
	}
	
	
	//返回验证码图片上的文本
	public String getText() {
		return text;
	}
	
	//保存图片到指定的输出流
	public static void output(BufferedImage image,OutputStream out) 
				throws IOException{
		ImageIO.write(image, "JPEG", out);
	}
}